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In this article, we propose a mapping method in which the system function of filter in z-domain is founded by discrete-time domain techniques as well as by chain-scatte ring matrices of various transmission-lines is derived to fulfill a dualbandpass microwave filter based on equal-length nonuniform coupled lines. A dualband filter with the desired bandwidth and low insertion loss is recognized by cascading bandpass and bandstop filters. The five-order Butterworth bandstop filter, which uses a coupled-serial-shunted lines structure, causes the implantation and correct placement of the bandstop filter. The wide-band bandpass filter is implemented by the five-order Chebyshev Type II band-pass filter, which uses serial lines and shunted stubs lines configuration. The design process is finished by using optimization algorithms to tune the values of characteristic impedances of each transmission-line section. Experimental results significantly agree with the theoretical values. Measurement shows that the 3 dB passband widths are about 20% for the frequency of 2.45 GHz and 10% for the frequency of 5.25 GHz. The insertion loss is about 0.831 dB at the frequency of 2.38 GHz and 1.873 dB at the frequency of 5.216 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 210–215, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22075 [ABSTRACT FROM AUTHOR]

The bilinear transformation is employed to represent the trapezoidal-rule integrator in the Z domain. This formulation, in conjunction with the representations of transmission-line elements in the Z domain, leads to the transmission-line configuration that is eligible for a microwave integrator. A microstrip circuit is implemented to verify the feasibility of the technique. Except for the lower-frequency band, the experimental results are in good agreement with the theoretical values of the trapezoidal-rule integrator. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 822–825, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21485 [ABSTRACT FROM AUTHOR]

A wideband differentiator is implemented by using nonuniform transmission lines. To utilize the transfer function of a differentiator developed in a study of discrete signal processing (DSP), we formulate the scattering characteristics of equal-length electrical transmission line sections in the Z domain. A uniform line shunted with a two-section stub is obtained to emulate the transfer function of a stable second-order recursive differentiator. A microstrip circuit is implemented to verify this novel method and experimental results are in good agreement with theoretical design parameters. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 226–228, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10877 [ABSTRACT FROM AUTHOR]